Options to buy for less than someone owes on a property

[Cory Wells]

I have an off market deal I am looking at where the price I would like to offer is around 8-10K less than what the seller currently owes. I brought up the idea of purchasing subject to his existing mortgage from the realtor who is representing him, but they asked how would we report that at the closing table. So I am not sure if I can purchase this property subject to if there is already a realtor in place, or can I just pay them the commission outside the sale and not have an actual closing? The realtor has not listed this property on the MLS. Seller seems very motivated per discussion and is willing to just walk away from the property and let the bank foreclose. My all in price with rehab would be around 50K-55K, ARV is around 74K, and the rent is 800. My plan is to hold as a rental. Any ideas on how to make this work other than the seller bringing 8K to closing?